This invention relates to methods and apparatus for determining an optical distance, such as a distance of an object within a field of view, and more particularly to a method and apparatus for scanning distances within a field of view.
A conventional camera includes an objective lens and a light detector, such as a photographic film, CCD array or other photosensitive device or structure. Light from a viewing environment enters the camera through the objective lens and impinges on the light detector. The portion of the viewing environment for which light enters is the camera's field of view. Some cameras pass the light to a viewfinder or eyepiece allowing an operator to select a desired field of view from the background environment. To take a picture or record, the light detector captures frames of the background light from the field of view.
Often the field of view is divided into discrete picture elements or pixels. In conventional digital video cameras the light detector records data for each pixel within the field of view for a given video frame. The data includes color, intensity and the pixel coordinates (i.e., x,y coordinates).
Conventional still cameras and video cameras include optics for focusing within the field of view. Thus, an operator can select to focus on a near field object or a far field object. Some cameras even include autofocus devices which automatically adjust the focal length of the objective lens to focus within the field of view.